Re: Record Position in Ordered Selection

[Peter Brawley]

Alan,

With a big table, self-joins are slow. They don't scale. As suggested by another poster, it can be faster to create creating a temp table ...

DROP TABLE IF EXISTS tmp;
SET @i=0;
CREATE TEMPORARY TABLE tmp
SELECT idcol,valuecol,@i:=@i+1 AS rank
ORDER BY valuecol DESC;

but handling ties will need another pass, which will again be slow.

PB
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